We used to be on Heroku and the cost wasn't just the high monthly bill - it was asking "is this little utility app I just wrote really worth paying $15/month to host?" before working on it.
This year we moved to a self-hosted setup on Coolify and have about 300 services running on a single server for $300/month on Hetzner. For the most part, it's been great and let us ship a lot more code!
My biggest realization is that for an organization like us, we really only need 99% uptime on most of our services (not 99.99%). Most developer tools are around helping you reach 99.99% uptime. When you realize you only need 99%, the world opens up.
Disco looks really cool and I'm excited to check it out!